1. Field of the Invention
The present invention relates to a novel compound and an asymmetric synthesis reaction useful for synthesis of a group of compounds including the novel compound.
2. Description of the Related Art
It is said that carriers of hepatitis C virus (HCV) are about two million in Japan and about two hundred million in the world. About 50% of these patients develop chronic hepatitis, and about 20% of them suffer from liver cirrhosis or liver cancer after more than 30 years have passed since infection. Therefore, there has been a demand for establishment of an effective method for treating hepatitis C.
Interferon therapy has been known as an effective method for eliminating HCV. However, patients to which interferon is effective are about ⅓ of all the patients.
In view of this, further developments have been made and at present, a main anti-virus therapy is a PEG-interferon/ribavirin combination therapy using pegylated interferon and ribavirin (1-β-D-ribofuranosyl-1H-1,2,4-triazole-3-carboxyamide) in combination.
However, patients to which even such a PEG-interferon/ribavirin combination therapy is significantly effective are about half of all the patients. Also, the HCV tends to mutate since it is a single-stranded RNA virus, which raises concerns that resistant viruses may arise by use of pharmaceutical drugs targeting viral proteins.
Under such circumstances, demand has arisen for development of an anti-HCV agent targeting host's factors (human cells). The HCV uses the lipid raft portion for anchorage of growth, and hence serine palmitoyltransferase (SPT) inhibitor has been attracting attention, which shows an effect of inhibiting formation of the lipid raft in cells. NA255 expressed by the following structural formula, which is the SPT inhibitor, has been proposed as an anti-HCV agent (see, for example, Sakamoto, H., Okamoto, K. et al., Nat. Chem. Biol., 1, 333-337 (2005)).

The SPT inhibitor involves few side effects and has been expected as an anti-HCV drug.
However, the NA255 is generally produced from Fusarium sp. F1476 strain, and cannot be said to be suitable for production on a large scale. Therefore, there has been a demand that such a compound expected as an anti-HCV drug be synthesized by a technique of synthetic organic chemistry.
In one proposal, the NA255 and similar substances are synthesized by a technique of synthetic organic chemistry (see, for example, International Publication No. WO2004/071503). This proposal technique, as shown in the following reaction scheme, synthesizes an optically active substance (compound g) which is an intermediate in syntheses of compounds such as the NA255, and has a problem that it is necessary to use a stoichiometric amount of an asymmetric catalyst (L-(+)-diethyl tartrate/Ti(OiPr)4).

In compound f and compound g, “TBDPS” denotes a tert-butyldiphenylsilyl group, and “OiPr” denotes an isopropoxy group.
Therefore, at present, there is a demand to provide a novel compound which enables compounds useful for production of pharmaceutical drugs such as anti-hepatitis C virus drugs to be synthesized at low cost by a technique of synthetic organic chemistry; and an asymmetric synthesis reaction useful for synthesis of a group of compounds including the novel compound.